1. Technical Field
Various embodiments relate generally to a semiconductor memory device and a programming method thereof.
2. Related Art
A semiconductor memory device is a storage device that is realized using a semiconductor made from, for example, silicon (Si), germanium (Ge), gallium arsenide (GaAs), or indium phosphide (InP). Semiconductor memory devices can be classified as volatile memory devices or nonvolatile memory devices.
A volatile memory device is unable to retain its stored data when the power is turned off. The volatile memory device includes a static random access memory (SRAM) device, a dynamic RAM (DRAM) device, a synchronous DRAM (SDRAM) device, or the like. A non-volatile memory device can retain its stored data even when powered off. The non-volatile memory device may include a read only memory (ROM) device, a programmable ROM (PROM) device, an electrically programmable ROM (EPROM) device, an electrically erasable and programmable ROM (EEPROM) device, a flash memory device, a phase-change RAM (PRAM) device, a magnetic RAM (MRAM) device, a resistive RAM (RRAM) device, a ferroelectric RAM (FRAM) device, or the like. A flash memory device may be classified as a NOR type or a NAND type.
The degree of integration of a semiconductor memory device has gradually increased over time. However, with the increased degree of integration of the semiconductor memory device, problems have arisen in the operations of the semiconductor memory device, such as coupling between neighboring cells, a wider threshold voltage distribution width resulting from a program disturb, or increased programming time to reduce the threshold voltage distribution width.